Optical measurement apparatus

ABSTRACT

An optical measurement apparatus configured to measure a photonic integrated circuit (photonic IC) is provided. The optical measurement apparatus includes a substrate, at least one optical waveguide device, a first connector, and a second connector. The at least one optical waveguide device is disposed on the substrate. The first connector and the second connector are connected with the at least one optical waveguide device. An optical signal from a first optical fiber is transmitted to the at least one optical waveguide device through the first connector, transmitted to the inside of the photonic IC though at least one first evanescent coupler of the photonic IC, transmitted to the at least one optical waveguide device through at least one second evanescent coupler of the photonic IC, and transmitted to a second optical fiber through the second connector in sequence.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 107143321, filed on Dec. 3, 2018. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

TECHNICAL FIELD

The disclosure relates to an optical measurement apparatus.

BACKGROUND

In a general semiconductor production process, wafer acceptance test(WAT) is a considerably important in-line test as a basis to judgewhether the manufacturing process is acceptable and whether the die isgood or bad; also, the test serves as a direct proof of monitoringvariations of the manufacturing process.

Besides, compared to the traditional production semiconductor process ofelectronic integrated circuits, silicon optical waveguides of photonicintegrated circuits (photonic ICs) may meet several different problemsin manufacturing such as: 1. the layout is more difficult and the designrule checking is more complicated; 2. the structural roughness and etchdepth obtained by the manufacturing process is more sensitive; 3. theperformance of device process cannot be verified quickly, and themeasurement method of optical input and optical output is morecomplicated than the measurement method of electrical test.

A known measurement method of photonic IC is to fabricate a diffractiongrating on a structure of a silicon optical waveguide, and an opticalfiber aligns to the diffraction grating to receive diffracted light fromthe diffraction grating to achieve the purpose of optical output.However, adopting the method is likely to make it uneasy for the opticalfiber to align to the diffraction grating with highly precise alignmentrequirement; thus, it is more difficult for the method to achieve thepurpose of optical output. Besides, limited by the size of thediffraction grating and the optical fiber, it is difficult to achievemultiple optical inputs and output ports in a limited area of anphotonic IC chip, and an array test is not easy.

SUMMARY

An embodiment of the disclosure provides an optical measurementapparatus configured to measure a photonic integrated circuit. Theoptical measurement apparatus includes a substrate, at least one opticalwaveguide device, a first connector and a second connector. The at leastone optical waveguide device is disposed on the substrate. The firstconnector and the second connector are connected to the at least oneoptical waveguide device. The at least one optical waveguide deviceincludes a first optical waveguide and a second optical waveguideseparated from each other. The first optical waveguide is connected tothe first connector, and the second optical waveguide is connected tothe second connector. An optical signal from a first optical fiber issequentially transmitted to the first optical waveguide device throughthe first connector, transmitted to the inside of the photonic IC thoughat least one first evanescent coupler of the photonic IC, transmitted tothe second optical waveguide device though at least one secondevanescent coupler of the photonic IC and transmitted to at least onesecond optical fiber through the second connector.

Several exemplary embodiments accompanied with figures are described indetail below to further describe the disclosure in details.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide further understanding,and are incorporated in and constitute a part of this specification. Thedrawings illustrate exemplary embodiments and, together with thedescription, serve to explain the principles of the disclosure.

FIG. 1 is a schematic view of an optical measurement apparatus and aphotonic integrated circuit (photonic IC) chip according to anembodiment of the disclosure.

FIG. 2 is a partial schematic view of the photonic IC chip in FIG. 1.

FIG. 3A is a schematic view when the optical measurement apparatus inFIG. 1 has not performed measurement to the photonic IC chip.

FIG. 3B is a schematic view when the optical measurement apparatus inFIG. 1 performs measurement to the photonic IC chip.

FIG. 4 is another variation of an optical waveguide device in an opticalmeasurement apparatus.

FIG. 5 is a top view and a side view showing a correspondingrelationship of an evanescent coupler and an optical waveguide devicewhen the optical measurement apparatus of FIG. 4 is performingmeasurement to an optical IC chip.

FIG. 6 is a top view and a sectional view showing a correspondingrelationship of an evanescent coupler and an optical waveguide devicewhen an optical measurement apparatus performs measurement to a photonicIC chip according to another embodiment of the disclosure.

FIG. 7A is a side schematic view of an evanescent coupler and an opticalwaveguide device when an optical measurement apparatus measures aphotonic IC chip according to an embodiment of the disclosure.

FIG. 7B is a perspective schematic view of a connector, an opticalwaveguide device and a photonic IC chip in FIG. 7A.

FIG. 8 shows a corresponding relationship among a substrate and opticalwaveguide devices of an optical measurement apparatus and evanescentcouplers of a photonic IC chip according to an embodiment of thedisclosure.

FIG. 9 is a bottom schematic view of a partial structure of an opticalmeasurement apparatus according to an embodiment of the disclosure.

FIG. 10A is a sectional schematic view of an optical measurementapparatus according to another embodiment of the disclosure.

FIG. 10B is a perspective schematic view of a partial structure of anoptical measurement apparatus according to still another embodiment ofthe disclosure.

FIG. 11 is a sectional schematic view of an optical measurementapparatus according to yet another embodiment of the disclosure.

FIG. 12 is a sectional schematic view of an optical measurementapparatus according to another embodiment of the disclosure.

FIG. 13 is a sectional schematic view of an optical measurementapparatus according to still another embodiment of the disclosure.

FIG. 14 is a sectional schematic view of an optical measurementapparatus according to yet another embodiment of the disclosure.

FIG. 15 is a sectional schematic view when an optical measurementapparatus has not yet measured a photonic integrated circuit accordingto another embodiment of the disclosure.

FIG. 16 is a sectional schematic view when the optical measurementapparatus in FIG. 15 is measuring the photonic IC.

FIG. 17 is a process chart of an optical measurement method according toan embodiment of the disclosure.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a schematic view of an optical measurement apparatus and aphotonic integrated circuit (photonic IC) chip according to anembodiment of the disclosure; FIG. 2 is a partial schematic view of thephotonic IC chip in FIG. 1; FIG. 3A is a schematic view when the opticalmeasurement apparatus in FIG. 1 has not yet performed a measurement tothe photonic integrated circuit chip; FIG. 3B is a schematic view whenthe optical measurement apparatus in FIG. 1 performs a measurement tothe photonic IC chip; FIG. 4 is another variation of an opticalwaveguide device in an optical measurement apparatus; and FIG. 5 is atop view and a side view showing a corresponding relationship between anevanescent coupler and an optical waveguide device when the opticalmeasurement apparatus of FIG. 4 performs a measurement to the photonicIC chip.

Please refer to FIG. 1 to FIG. 5, an optical measurement apparatus 200in this embodiment is configured to measure a photonic integratedcircuit (photonic IC), which is, for example, a photonic IC chip 100. Inthe manufacturing process of the photonic IC chip 100, a plurality ofphotonic IC chips 100 arranged in an array matrix may be manufactured ona wafer, and the photonic IC chips 100 are separated by scribe lines 60.The optical measurement apparatus 200 includes a substrate 210, at leastone optical waveguide device 220 (a plurality of optical waveguidedevices 220 are shown as an example in FIG. 1), a first connector 230and a second connector 240. The at least one optical waveguide device220 is disposed on the substrate 210. The first connector 230 and asecond connector 240 are connected to the at least one optical waveguidedevice 220.

When the optical measurement apparatus 200 measures the photonic IC chip100, an optical signal 72 from a first optical fiber 40 is sequentiallytransmitted to the at least one optical waveguide device 220 through thefirst connector 230, transmitted to the inside of the photonic IC chip100 from the at least one optical waveguide device 220 through at leastone first evanescent coupler 110 a of the photonic IC chip 100,transmitted to the at least one optical waveguide device 220 from theinside of the photonic IC chip 100 through at least one secondevanescent coupler 110 b of the photonic IC chip 100, and transmitted toa second optical fiber 50 from the at least one optical waveguide device220 through the second connector 240.

In the present embodiment, the photonic IC chip 100 includes a pluralityof evanescent couplers 110 including the abovementioned at least onefirst evanescent coupler 110 a and the abovementioned at least onesecond evanescent coupler 110 b, and an evanescent coupler 110 are shownin FIG. 2 as a representative. In addition, the photonic IC chip 100further includes a substrate 140, a buried oxide layer 150, a pluralityof waveguides 120 and a plurality of devices 130. The substrate 140 is,for example, a silicon substrate. The buried oxide layer 150 is disposedon the substrate 140. The evanescent couplers 110, waveguides 120 andthe plurality of devices 130 are disposed on the buried oxide layer 150.The waveguides 120 are, for example, silicon waveguides. The pluralityof devices 130 may include a multiplexing and demultiplexing device 131,a photodetector 132, a transimpedance amplifier 133, a modulator 134, alaser diode 135, a monitor 136, other electronic or optoelectronicdevices or suitable combinations thereof, wherein the waveguides 120 mayconnect the multiplexing and demultiplexing device 131, photodetector132, modulator 134, laser diode 135 and monitor 136 so as to make theoptical signal 72 transmitted among the plurality of devices 130. Thetransimpedance amplifier 133 may be electrically connected to thephotodetector 132 to amplify the electrical signal from thephotodetector 132.

In an embodiment of FIG. 3A, the optical waveguide device 220 is anoptical waveguide extended to a second connector 240 from a firstconnector 230. However, in an embodiment of FIG. 4, the opticalwaveguide device 220 a includes a first optical waveguide 222 and asecond optical waveguide 224 separated from each other, wherein thefirst optical waveguide 222 is connected to the first connector 230, andthe second optical waveguide 224 is connected to the second connector240. In the present embodiment, the material of the optical waveguidesdevice 220 and 220 a are, for example, silicon nitride, siliconoxynitride or polymer, but is not limited hereto. In the embodiments ofFIG. 1 and FIG. 3A, the length of the optical waveguide (which is theoptical waveguide device 220) is equal to or slightly greater than theshortest distance between the first connector 230 and the secondconnector 240, which means that the optical waveguide is extended as astraight line, but the disclosure is not limited hereto.

An end of the evanescent coupler 110 is a tapered end. In the presentembodiment, the width of the end of the evanescent coupler 110 in thedirection parallel to the surface of the substrate 140 is tapered;however, the thickness thereof in the direction perpendicular to thesurface of the substrate 140 is kept constant as shown in FIG. 5.Besides, in an embodiment of FIG. 4, an end of the optical waveguide 222closed to the first evanescent coupler 110 a is a tapered end, and anend of the second optical waveguide 224 closed to the second evanescentcoupler 110 b is a tapered end. In the present embodiment, the widths ofthe ends of the first optical waveguide 222 and the second opticalwaveguide 224 in the direction parallel to the surface of the substrate210 are tapered; however, the thickness thereof in the directionperpendicular to the substrate 140 is kept constant.

In the present embodiment, when the optical measurement apparatus 200measures the photonic IC chip 100, the optical waveguide device 220 or220 a directly contacts the first evanescent coupler 110 a, and directlycontacts the second evanescent coupler 110 b. In an embodiment of FIG.3B, a part of the optical signal 72 from the first connector 230 andtransmitted in the optical waveguide device 220 are transmitted to thewaveguide 120 (a silicon waveguide, for example) in the photonic IC chip100 through the first evanescent coupler 110 a. The optical signal 72transmitted in the waveguide 120 is then transmitted to the opticalwaveguide device 220 through the second evanescent coupler 110 b. Inaddition, as shown in FIG. 3A, when the optical measurement apparatus200 does not measure the photonic IC chip 100, the optical signal 72from the first connector 230 is directly transmitted to the secondevanescent coupler 110 b through the optical waveguide device 220 and isoutput through the second optical fiber 50, the obtained optical signal72 obtained by which may be used to calibrate the optical measurementapparatus 200.

In the present embodiment, as shown in FIG. 1, a light source 70 may bedisposed on an end of the first optical fiber 40, and the optical signal72 emitted by the light source 70 is input into the optical measurementapparatus 200 through the first optical fiber 40. On the other hand, anoptical power meter 80 or any other photodetector may be disposed on anend of the second optical fiber 50. The optical measurement apparatus200 may output the optical signal 72 to the optical power meter 80through the second optical fiber 50. In an embodiment of FIG. 3B, withthe power of the optical signal 72 measured by the optical power meter80, whether the measured photonic IC chip 100 is good or bad may bedetermined. On the other hand, by comparing the power of the opticalsignal 72 obtained by the optical power meter 80 under the scenario FIG.3A (not during measurement) with that under the scenario of FIG. 3B(during measurement), whether the measured photonic IC chip 100 is goodor bad may be determined more accurately.

In addition, in an embodiment of FIG. 4, when the optical measurementapparatus 200 a measures the photonic IC chip 100, the first opticalwaveguide 222 directly contacts the first evanescent coupler 110 a, andthe second optical waveguide 224 directly contacts the second evanescentcoupler 110 b. The optical signal 72 from the first connector 230 isinput into the first optical waveguide 222, and the optical signal 72transmitted in the first optical waveguide 222 is transmitted to thewaveguide 120 (a silicon waveguide, for example) in the photonic IC chip100 through the first evanescent coupler 110 a. The optical signal 72transmitted in the waveguide 120 is transmitted to the second opticalwaveguide 224 through the second evanescent coupler 110 b, and theoptical signal transmitted in the second optical waveguide 224 istransmitted to the second optical fiber 50 through the second connector240.

In embodiments of FIGS. 3A, 3B and 4, the optical measurement apparatus200, 200 a further includes a holder 250, wherein the substrate 210 isdisposed on the holder 250. In the abovementioned embodiment, thesubstrate 210 is located between the optical waveguide device 220 andthe holder 250. Besides, the photonic IC chip 100 may further include aninsulating layer 160, covering the waveguide 120 and the devices 130,wherein the refractive index of the insulating layer 160 is lower thanthe refractive index of the optical waveguide device 220, 220 a, andlower than the refractive index of the waveguide 120. Moreover, therefractive index of the optical waveguide device 220, 220 a may begreater than the refractive index of the first optical fiber 40 and thesecond optical fiber 50. Also, the optical measurement apparatus 200,200 a may further include a holding layer 260 disposed beside theoptical waveguide device 220. If the optical measurement apparatuses200, 200 a has a plurality of optical waveguide devices 220 (as shown inFIG. 1) or a plurality of waveguide devices 220 a, and the holding layer260 may be filled in the space between the plurality of opticalwaveguide devices 220, 220 a. In addition, the refractive index of theoptical waveguide devices 220, 220 a is greater than the refractiveindex of the holding layer 260, and the material of the holding layer260 is, for example, polymer.

In the optical measurement apparatus 200, 200 a of the presentembodiment, since the optical waveguide device 220, 220 a is adopted toperform the input and output of the optical signal to and from theevanescent couplers 110 on the photonic IC chip 100, the layout of theevanescent coupler 110 on the photonic IC chip 100 may not be limited bythe size and the measurement direction of the optical fibers. In otherwords, the layout of the optical waveguide device 220, 220 a may beadjusted with flexibility to serve as a bridge between the evanescentcoupler 110 and the optical fiber. Thus, the problem that the opticalfiber cannot align to the diffraction grating easily in the knowntechnology may not occur. Also, by the flexible adjustment of the layoutof the optical waveguide device 220, 220 a, the array test may beachieved easily. In addition, with the optical waveguide device 220, 220a, all the evanescent couplers 110 in different directions on thephotonic IC chip 100 may be measured at one time according to therequirement. Besides, the sizes of the optical waveguide devices 220 and220 a may be reduced, so as to greatly reduce the required area of theoptical input and output and not be limited by the size of the opticalfiber.

In the embodiment of FIG. 1, the plurality of first optical fibers 40,the plurality of optical waveguide devices 220 and the plurality ofsecond optical fibers 50 correspond to each other in a way of one toone, but the disclosure is not limited thereto. In other embodiments,one first optical fiber 40 may correspond to a plurality of opticalwaveguide devices 220, and correspond to one second optical fiber 50.Specifically, the optical signal 72 from the first optical fiber 40 isdivided into a plurality of sub-signals by the first connector 230 andare transmitted in the optical waveguide devices 220, respectively. Theplurality of sub-signals are transmitted to the plurality of firstevanescent couplers 110 a from the optical waveguides devices 220,respectively, and are transmitted to the optical waveguides device 220from the plurality of second evanescent couplers 110 b, respectively,and the plurality of sub-signals are merged into the optical signal 72,and are transmitted from the optical waveguide devices 220 to a secondoptical fiber 50 through the second connector 240. In the embodiment ofFIG. 1, the plurality of sub-signals are transmitted to the plurality ofsecond optical fibers 50 from the optical waveguide devices 220 throughthe second connector 240, respectively (as shown in FIG. 1). In thepresent embodiment, the optical signal 72 may be a light having widerwavelength range, and is split into sub-signals having differentnarrower wavelength ranges. In the end, the sub-signals are merged intothe optical signal 72 having a wider wavelength range.

FIG. 6 is a top view and a sectional view showing a correspondingrelationship of an evanescent coupler and an optical waveguide devicewhen an optical measurement apparatus is performing measurement to aphotonic IC chip according to another embodiment of the disclosure,wherein the three cross-sections at the bottom of the drawing arerespectively the cross-sections obtained by cutting the top view at thetop of the drawing along the three dotted lines. Please refer to FIG. 6,the evanescent coupler 110 may have multiple-layered structure, whereinan upper layer thereof may contact the optical waveguide device 220 a(as shown in the lower-middle cross-section of FIG. 6), and a lowerlayer thereof may be nearby the waveguide 120 (as shown in thelower-left cross-section of FIG. 6) and a material of the insulatinglayer 160 may be filled between each layer and between the lower layerand the waveguide 120. Besides, the optical coupler between each layermay adopt the method of evanescent coupling. In addition, the evanescentcoupler 110 in FIG. 6 may take the second evanescent coupler 110 b as anexample, but the same structure may also apply to the first evanescentcoupler 110 a.

FIG. 7A is a side schematic view of an evanescent coupler and an opticalwaveguide device when an optical measurement apparatus measures anphotonic IC chip according to an embodiment of the disclosure; FIG. 7Bis a perspective schematic view of a connector, an optical waveguidedevice and a photonic integrated circuit chip in FIG. 7A; FIG. 8 shows acorresponding relationship among a substrate and optical waveguidedevices of an optical measurement apparatus and evanescent couplers of aphotonic IC chip according to an embodiment of the disclosure; FIG. 9 isa bottom schematic view of a partial structure of an optical measurementapparatus according to an embodiment of the disclosure. Please refer toFIG. 7A, FIG. 7B, FIG. 8 and FIG. 9. From FIG. 7A, it can be known thatthe optical waveguide device 220 may be flexible to be suitable for thedisposed location of each connector (such as the first connector 230 andthe second connector 240). Besides, the plurality of optical waveguidedevices 220 may be fan-out from the ends of the plurality of opticalwaveguide devices 220 closed to the photonic IC chip 100 to ends thereofclosed to the connector, which means that spreading out like the shapeof a fan (as shown in FIG. 9), and the fan-out shape shown in 7B is likeFIG. 9 that includes a plurality of optical waveguide devices 220, andthere is a holding layer 260 filled between the adjacent opticalwaveguide devices 220 and on two sides of the plurality of opticalwaveguide devices 220. From FIG. 8, it can be known that the layoutlocations of the ends of the plurality of optical waveguide devices 220may correspond to the layout locations of the evanescent coupler 110 ofthe photonic IC chip 100, and may be located on the four edges of thesubstrate 210 or the scribe lines 60. Therefore, the measurementlocations are not limited by the measurement direction of the opticalfiber. The fan-out shape of the plurality of optical waveguide devices220 as shown in FIG. 9 only shows the optical waveguide device 220 atthe top of FIG. 9 as an example. In fact, the optical waveguide devices220 at both the right and left sides and the bottom side of FIG. 9 mayall have fan-out shapes and connectors connected thereto. In anembodiment, each of four sides of the substrate 210 may be provided witha connector, and the optical waveguide devices 220 at the four sides ofthe substrate 210 fan out to the connectors at the four sides,respectively. Or, in another embodiment, connectors may be disposed ontwo opposite sides of the substrate 210, and the plurality of opticalwaveguide devices 220 on the substrate 210 fan out and extend to theconnectors on the two opposite sides, respectively.

Please refer to FIG. 8 and FIG. 9. In the present embodiment, theplurality of optical waveguide devices 220 are coupled to the firstevanescent coupler 110 a, respectively, and are coupled to the secondevanescent coupler 110 b, respectively, wherein an interval D1 betweenneighbors of the first evanescent couplers 110 a or an interval D1between neighbors of the second evanescent coupler 110 b is less than aninterval D2 of the plurality of optical waveguide devices 220 at thefirst connector 230 and at the second connector 240. Thus, the densityand number of the evanescent couplers on the photonic IC chip 100 may begreater and not limited by the size of the optical fiber. Also thedifficulty of dense optical fiber alignment issue may not occur.

FIG. 10A is a sectional schematic view of an optical measurementapparatus according to another embodiment of the disclosure, and FIG.10B is a perspective schematic view of a partial structure of an opticalmeasurement apparatus of still another embodiment of the disclosure.Please refer to FIG. 10A. The optical measurement apparatus 200 c of thepresent embodiment is similar to the optical measurement apparatus 200of FIG. 3A, and the differences of the two apparatuses are as follows.In the optical measurement apparatus 200 c of the present embodiment,the length of an optical waveguide (which is an optical waveguide device220 c) is greater than the shortest distance between a first connector230 and a second connector 240; in other words, the optical waveguidehas a bendable part. In the present embodiment, the optical waveguide(which is the optical waveguide device 220 c) is bent to a side surface214 of the substrate 210 from a bottom surface 212 of a substrate 210.Besides, in the present embodiment, the first connector 230 and thesecond connector 240 may be disposed on the side surface of the holder250.

Please refer to FIG. 10B again. An optical measurement apparatus 200 bof the present embodiment is similar to the optical measurementapparatus of FIG. 9, and the differences between the two apparatuses areas follows. In the optical measurement apparatus 200 b of the presentembodiment, apart from the general fan-out as shown in FIG. 9, theplurality of optical waveguide devices 220 are bent to the side surfaceof the substrate and the side surface 252 of the holder 250 from thebottom surface of the substrate as shown in FIG. 10A after the fan-out,and are connected to the connector (the first connector 230 or thesecond connector 240, for example) on the side surface 252 of the holder250. As the description of FIG. 9, FIG. 10B only shows that the opticalwaveguide devices 220 at the right side of the drawing are bent upwardafter extending to the right. However, actually the optical waveguidedevices 220 at the front side, left side and back side in the drawingmay also be bent or be extended to the appropriate direction; andconnectors may be disposed on the four sides or the opposite two sidesof the holder 250, and the plurality of optical waveguide devices 220are respectively extended to the connectors disposed on the opposite twosides or the four sides.

FIG. 11 is a sectional schematic view of an optical measurementapparatus according to yet another embodiment of the disclosure. Pleaserefer to FIG. 11. An optical measurement apparatus 200 d of the presentembodiment is similar to the optical measurement apparatus 200 c of FIG.10A, and the differences between the two apparatuses are as follows. Inan optical measurement apparatus 200 d of the present embodiment, afterthe optical waveguide (which is the optical waveguide device 220 d) isbent to the side surface 214 of the substrate 210 from the bottomsurface 212 of the substrate 210, the optical waveguide is then bent tothe bottom surface 254 of the holder 250 and is extended along thebottom surface 254 of the holder 250 and lastly connected to theconnector 230, 240.

FIG. 12 is a sectional schematic view of an optical measurementapparatus according to another embodiment of the disclosure. Pleaserefer to FIG. 12. An optical measurement apparatus 200 e of the presentembodiment is similar to the optical measurement apparatus 200 of FIG.3B, and the differences between the two apparatuses are as follows. Theoptical measurement apparatus 200 e of the present embodiment furtherincludes a protective layer 270, covering the surface of the opticalwaveguide device 220. An optical signal 72 from the optical waveguidedevice 220 is transmitted to an evanescent coupler 110 a through theprotective layer 270, and the optical signal 72 from the secondevanescent coupler 110 b is transmitted to the optical waveguide device220 through the protective layer 270. In other words, when the opticalmeasurement apparatus 200 e measures the photonic IC chip 100, theprotective layer 270 contacts the first evanescent coupler 110 a and thesecond evanescent coupler 110 b. The refractive index of the protectivelayer 270 may be closed or consistent with the refractive index of theoptical waveguide device 220.

FIG. 13 is a sectional schematic view of an optical measurementapparatus according to still another embodiment of the disclosure.Please refer to FIG. 13. An optical measurement apparatus 200 f of thepresent embodiment is similar to the optical measurement apparatus 200 eof FIG. 12, and the differences between the two apparatuses are asfollows. The optical measurement apparatus 200 f of the presentembodiment adopts the optical waveguide device 220 a as shown in FIG. 4,which includes the first optical waveguide 222 and the second opticalwaveguide 224, wherein the protective layer 270 f covers the firstoptical waveguide 222, the second optical waveguide 224 and the bottomsurface 212 of the substrate 210.

FIG. 14 is a sectional schematic view of an optical measurementapparatus according to yet another embodiment of the disclosure. Pleaserefer to FIG. 14. An optical measurement apparatus 200 g of the presentembodiment is similar to the optical measurement apparatus 200 f of FIG.13, and the differences between the two apparatuses are as follows. Inthe optical measurement apparatus 200 g of the present embodiment, theprotective layer 270 g may be divided into a sub-protective layer 272 gand a sub-protective layer 274 g which are separated from each other andcover the first optical waveguide 222 and the second optical waveguide224, respectively, and the protective layer 270 g exposes a part of thebottom surface 212 of the substrate 210.

FIG. 15 is a sectional schematic view when an optical measurementapparatus has not yet measured a photonic IC according to anotherembodiment of the disclosure; and FIG. 16 is a sectional schematic viewwhen the optical measurement apparatus in FIG. 15 is measuring thephotonic IC. Please refer to FIG. 15 and FIG. 16. An optical measurementapparatus 200 h of the present embodiment is similar to the opticalmeasurement apparatus 200 of FIG. 3A, and the differences between thetwo apparatuses are as follows. The optical measurement apparatus 200 hof the present embodiment further includes a substrate 210, a holder 250and a redistribution layer (RDL) 290, a plurality of first electrodes292 and a plurality of electrical probes 280. The RDL 290 is, forexample, disposed on the holder 250 on the substrate 210. The pluralityof first electrodes 292 are disposed on the RDL 290. The plurality ofelectrical probes 280 penetrate through the substrate 210 and pass bythe optical waveguide device 220, and a part of each electrical probe280 is disposed on the holder 250. When the optical measurementapparatus 200 h measures the photonic IC chip 100 h, the electricalprobes 280 connect the plurality of first electrodes 292 with aplurality of second electrodes 170 of the photonic IC chip 100 h,respectively. The first electrodes 292 may be connected to an outerelectrical signal source and an electrical detector by the RDL 290, andthe second electrode 170 may be electrically connected to the device 130of the inside of the photonic IC chip 100 h. Thus, the electricalproperty of the photonic IC chip 100 h may be detected by the electricalprobes 280; and the optical measurement of the photonic IC chip 100 hmay be performed by the optical waveguide device 220.

FIG. 17 is a process chart of an optical measurement method according toan embodiment of the disclosure. The optical measurement method of thepresent embodiment may be performed by using the optical measurementapparatus of any embodiment mentioned above. The optical measurementapparatus 200 is used as an example for the following explanation.Please refer to FIG. 3B and FIG. 17. The optical measurement method ofthe present embodiment includes the following implemented steps.Firstly, step S110 is implemented to transmit an optical signal 72 froma first optical fiber 40 to at least one optical waveguide device 220through a first connector 230; then, step S120 is implemented totransmit the optical signal 72 from the at least one optical waveguidedevice 220 to the inside of a photonic IC (a photonic IC chip 100, forexample) through at least one first evanescent coupler 110 a of thephotonic IC; and then, step S130 is implemented to transmit the opticalsignal 72 from the inside of the photonic IC to the at least one opticalwaveguide device 220 through at least one second evanescent coupler 110b; afterward, step S140 is implemented to transmit the optical signal 72from the at least one optical waveguide device 220 to at least onesecond optical fiber 50 through a second connector 240. In the presentembodiment, the steps S110-S140 may be implemented naturally and insequence along with the transmission of the optical signal 72 when theoptical waveguide device 220 is closed to or contacts the firstevanescent coupler 110 a and the second evanescent coupler 110 b whenthe measurement is being performed.

The optical measurement method of the present embodiment may achieve theadvantages and effects of the optical measurement apparatuses of eachembodiment mentioned above, and the details are not described againhere.

In the embodiments of FIG. 1, FIG. 3A and FIG. 3B, when an opticalmeasurement apparatus 200 is adopted to measure a photonic IC chip 100,an optical waveguide device 220 directly contacts a first evanescentcoupler 110 a and directly contacts a second evanescent coupler 110 b.In the embodiment of FIG. 3B, a part of an optical signal 72 from afirst connector 230 and transmitted in the optical waveguide device 220is transmitted to a waveguide 120 (a silicon waveguide, for example) inthe photonic IC chip 100 through the first evanescent coupler 110 a. Theoptical signal 72 transmitted in the waveguide 120 is again furthertransmitted to the optical waveguide device 220 through the secondevanescent coupler 110 b. Besides, as shown in FIG. 3A, when the opticalmeasurement apparatus 200 does not measure the photonic IC chip 100, theoptical waveguide device 220 does not contact the first evanescentcoupler 110 a and the second evanescent coupler 110 b; thus, the opticalsignal 72 from the first connector 230 is directly transmitted to thesecond evanescent coupler 110 b through the optical waveguide device 220and is output through a second optical fiber 50, the optical signal 72obtained by which may be configured to calibrate the optical measurementapparatus 200. For example, an optical power meter 80 may beelectrically connected to a processor 81, and the processor 81 maycompare the optical signal 72 from the second optical fiber 50 detectedby the optical power meter 80 when the photonic IC chip 100 is measuredwith that when the photonic IC 100 is not measured, so as to achieve theeffect of calibrating the obtained optical signal 72 when measuring thephotonic IC chip 100.

In an embodiment, the processor 81 is, for example, a central processingunit, (CPU), a microprocessor, a digital signal processor (DSP), aprogrammable controller, a programmable logic device (PLD) or othersimilar devices or combinations of the devices thereof, and thedisclosure is not limited thereto. Besides, in an embodiment, eachfunction of the processor 81 may be implemented as a plurality ofprogram codes. The plurality of program codes may be stored in a memoryand the plurality of program codes are executed by the processor 81. Or,in an embodiment, each function of the processor 81 may be implementedas one or a plurality of circuits. The disclosure does not limit whetherto use the way of software or of hardware to implement each function ofthe processor 81.

Based on above, in the optical measurement apparatus and method of thepresent embodiment, since the optical waveguide device is adopted to bealigned with and contact the evanescent coupler on the photonic IC chipso as to perform the input and output of the optical signal, the layoutof the evanescent couplers on the photonic IC chip is not limited by thesize and measurement direction of the optical fiber. In other words, thelayout of the optical waveguide device may be adjusted flexibly to serveas a bridge between the evanescent coupler and the optical fiber;therefore, the problem that the optical fiber cannot align with thediffraction grating easily in the known technology may not occur.Besides, by the flexible adjustment of the layout of the opticalwaveguide device, the array test may be achieved easily.

Besides, in the optical measurement apparatus and method of the presentembodiment, an interval of the plurality of optical waveguide devices atthe first connector and at the second connector is greater than aninterval between neighbors of the plurality of first evanescent couplersand greater than an interval between neighbors of the plurality ofsecond evanescent couplers. Therefore, the density and number of theevanescent couplers on the photonic IC chip may be more and may not belimited by the size of the optical fiber; also, the difficulty ofoptical fiber alignment issue may not occur.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of thedisclosed embodiments without departing from the scope or spirit of thedisclosure. In view of the foregoing, it is intended that the disclosurecover modifications and variations of this disclosure provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. An optical measurement device, configured tomeasure a photonic integrated circuit (photonic IC), the opticalmeasurement device comprising: a substrate; at least one opticalwaveguide device disposed on the substrate; and a first connector and asecond connector which are connected to the at least one opticalwaveguide device, wherein the at least one optical waveguide devicecomprises a first optical waveguide and a second optical waveguideseparated from each other; the first optical waveguide is connected tothe first connector and the second optical waveguide is connected to thesecond connector; an optical signal from a first optical fiber issequentially transmitted to the first optical waveguide through thefirst connector, transmitted to an inside of the photonic IC through atleast one first evanescent coupler of the photonic IC, transmitted tothe second optical waveguide through at least one second evanescentcoupler of the photonic IC, and transmitted to at least one secondoptical fiber through the second connector.
 2. The optical measurementapparatus according to claim 1, wherein one end of the first opticalwaveguide closest to the first evanescent coupler is a tapered end, andone end of the second optical waveguide closest to the second evanescentcoupler is a tapered end.
 3. The optical measurement apparatus accordingto claim 1, further comprising a holder, wherein the substrate isdisposed on the holder.
 4. The optical measurement apparatus accordingto claim 1, further comprising a protective layer, covering surfaces ofthe first optical waveguide and the second optical waveguide.
 5. Theoptical measurement apparatus according to claim 1, wherein the at leastone optical waveguide device is a plurality of optical waveguidedevices, and the at least one second optical fiber is a plurality ofsecond optical fibers; optical signals in the plurality of opticalwaveguide devices are respectively transmitted to the plurality ofsecond optical fibers through the second connector.
 6. The opticalmeasurement apparatus according to claim 1, wherein the at least oneoptical waveguide device is a plurality of optical waveguide devices;the at least one first evanescent coupler is a plurality of firstevanescent couplers, and the at least one second evanescent coupler is aplurality of second evanescent couplers; an interval between theplurality of optical waveguide devices at the first connector and thesecond connector is greater that an interval between neighbors of theplurality of first evanescent couplers, and greater than an intervalbetween neighbors of the plurality of second evanescent couplers.
 7. Theoptical measurement apparatus according to claim 1, further comprising:a plurality of electrical probes, penetrating through the substrate andpassing by the at least one optical waveguide device, wherein, when theoptical measurement apparatus measures the photonic IC, the plurality ofelectrical probes are respectively connected to a plurality ofelectrodes of the photonic IC.